1. Technical Field of the Invention
The present invention relates generally to experimental data collection, display and analysis and specifically to gathering, organizing and visually displaying information from multiple data sources.
2. Discussion of the Related Art
When designing devices for use by human operators it is useful to determine how an individual will interact with the new device. One method of doing this quantitatively is to monitor certain physical reactions by the operator such as heart rate, skin temperature, gross physical movements of the operator and where the subject is looking. In most cases this is done by using several separate machines, each with its own display medium and recording facility. This requires an experimenter to attend to several different data displays of different types and formats which may be physically distant from each other. A further drawback of multiple monitoring systems is that retrospective analysis of the data requires time synchronization of the several types of data recordings which may be difficult.
Another factor that may be observed to study the interaction between an operator and a device is an index of engagement. During operation of a task set, electroencephalographic (EEG) signals may be used to reflect an operator's engagement in the task set. An index of engagement may be defined that is an indication of the operator's engagement. One such index, using EEG signals, defined as beta power/ (alpha power+theta power) was found to be a useful engagement index in a paper by Pope, Alan T., Bogart, Edward H. and Bartolome, Debbie S., "Biocybernetic system evaluates indices of operator engagement in automated task," Biological Psychology 40 (1995) 187-195.
This engagement index may be used to design a negative feedback system for monitoring of automated tasks such that as an operator is found to have decreased attention, the level of automation is reduced. The reduction in automation levels means that there is an increased task demand on the operator which increases the operator's level of engagement. Similarly a positive feedback system may be employed such that as the operator's level of engagement drops, the automation level of the tasks is increased, decreasing the demand on the operator. A negative feedback system produces stable short-cycle oscillation in engagement index while a positive feedback system produces longer, more variable periods of oscillation in engagement index.
Others have produced products or patents dealing with the problem of displaying multiple signals in a single display.
Telefactor Corp. of W. Conshohocken, PA produces a device for the collection and display of multiple EEG or electrocardiograph (ECG) signals. It includes video output capability to standard video tape recorders and the ability to superimpose waveforms onto a video signal.
Hiromoto et. al. (U.S. Pat. No. 5,200,734) disclose a system for monitoring a plant in which a plurality of interactive functions for control of a plant are displayed on a screen simultaneously. The system uses discriminating means to determine which interactive functions are displayed and in which order they are presented so that the most likely functions to be used are readily available to the user. The data used by the discriminating means are collected from a plurality of monitoring devices and processed in a computer.
Beaudin et. al. (U.S. Pat. No. 5,250,933) disclose a system for simultaneous display of multiple images on a single video display device. The system of the '933 patent is a windowing system that allows for windowing of digital or analog video and for independent color mapping for each window. This system incorporates the ability to read from or output to a video tape recorder (hereafter VTR) so that retrospective analysis of the images may be made.
Dinwiddie Jr. et. al. (U.S. Pat. No. 5,434,590) disclose a multimedia system for simultaneous display of multiple image signals, including full motion video signals, the image signals derived from a plurality of media sources. Image signals pass through a media bus to a media control module which, in turn provides a composed image signal to a display device.
Siann et. al. (U.S. Pat. No. 4,406,306) disclose a system for displaying information from a graphics memory and a video memory on a display monitor. The graphics data is displayed on the display monitor and the video data is displayed in a window in the display monitor.
Moon et. al. (U.S. Pat. No. 4,804,950) disclose a system for multichannel data acquisition and display for signal monitoring. The system of the '950 patent is used for patient monitoring by a plurality of devices. The data from the monitoring instruments passes through dedicated module and channel tables which in turn supply the data to display windows in a single display device.